Alcohol alkoxylate containing materials have been used in a wide variety of industrial applications, for example as nonionic surfactants. They are typically prepared by the reaction of an alcohol with an alkylene epoxide such as ethylene oxide (i.e. oxirane) or propylene oxide (i.e. 2-methyoxirane) in the presence of one or more catalysts. Fluorinated alkylalkoxylates which are prepared by the reaction of an alcohol incorporating a fluorinated alkyl group with an alkylene epoxide are an important class of materials. Fluorinated alkylalkoxylates are especially useful in several industrial applications, including use as nonionic surfactants in the manufacture of PVC films, electrochemical cells, and various photographic coatings.
Known catalyst systems and processes for the alkoxylation of fluorinated alcohols include using Lewis acids such as boron trifluoride or silicon tetrafluoride, alone in combination with metal hydrides, fluorides, alkyls or alkoxides. Such acidic materials also catalyze side reactions such as dimerization of alkylene epoxides to form dioxanes during the alkylalkoxylation. For this reason many processes use strongly basic catalysts to alkoxylate alcohols. However, some alcohols are not stable to strong base. For instance, in the presence of strong base some hydrofluorocarbons are prone to elimination of HF and the formation of fluorinated olefins. Halohydrins, XCR2CR2OH, are well known to form epoxides in the presence of base and are used for this purpose synthetically to convert olefins to epoxides.
Halling and Huang in U.S. Pat. No. 5,608,116 disclose a process for the preparation of fluoralkylalkoxylates in which a commercial mixture of perfluoroalkylethanols having the general structure RfCH2CH2OH are alkoxylated in the presence of a catalyst system comprising an iodine source and alkali metal borohydride such as NaBH4, an expensive material that presents safety concerns due to flammability.